TORONTO - If you thought that the Tyrannosaurus rex was something to be afraid of, meet Siats meekerorum.
The newly-discovered dinosaur belongs to a species of carcharodontosaur, a group of giant meat-eaters including some of the largest predators ever discovered. The only other carcharodontosaur discovered in North America was Acrocanthosaurus, discovered in 1950.
“It’s been 63 years since a predator of this size has been named from North America,” said Lindsay Zanno, a North Carolina State University paleontologist, and lead author of the Nature Communications paper describing the new find. “You can’t imagine how thrilled we were to see the bones of this behemoth poking out of the hillside.”
Siats lived alongside and competed with the yet-to-be-fully-developed tyrannosaurs. In fact, if it wasn’t for the end of the carcharodontosaurs, the T-rex may not have gained the title as the fiercest predator of its time.
Paleontologists from North Carolina State University discovered the partial skeleton of the new species of carnivorous dinosaur in Utah’s Cedar Mountain Formation in 2008. They estimate that it was more than 30 feet long and weighed at least four tons – and that it was just a baby. An adult, they theorize, would be as large as an Acrocanthosaurus, which would be 40 feet and 6 tons.
The smaller tyrannosaurs would be nothing but a small nuisance to them at the time.
Paleontologists had long wondered who the king of the Late Cretaceous was. There had been a gap of 30 million years in the fossil record from when the top seat switched from the carcharodontosaur to the tyrannosaurs.
What paleontologists believe is that the large size of Siats prevented smaller tyrannosaurs from taking the top spot earlier than they did. Only after the carcharodontosaurs disappeared could the T-rex climb to the top. It took 30 million years, but once T-rex developed into the top predator, it weighed twice as much as the Siats.
And it gets even more interesting: though Siats and Acrocanthosaurus belong to the same species, they belong to different sub-groups. Siats belongs to Neovenatoridae, which is a more slender group of carcharodontosaur – a sub-group that has never before been found in North America.
The dinosaur is named after the cannibalistic man-eating monster from the Ute tribal legend, Siats, as well as the Meeker family which supported palentologists at the Field Museum.
The team said that two other discoveries have been made in the region.
“Stay tuned,” added Zanno. “There are a lot more cool critters where Siats came from.”
© Shaw Media, 2013